1. Field of the Invention
This invention in one embodiment relates to improvements in and relating to adjustable supports and more particularly but not exclusively to adjustable supports suitable for use in holding, at a desired angle, items of office equipment.
In one particular application of the adjustable support of the present invention it may provide a desired angle of operation for a document holder, known as a "copy holder" used by computer operators and typists for holding written documents as the keyboard work is being effected. However, innumerable uses of the invention will become apparent to those skilled in the engineering arts such as use for folding benches, electrical appliances such as fans and heaters, and furniture for example.
2. Description of Background Art
To the present time adjustable supports or stands have typically used a swivel joint consisting of a ball joint about which the support can swivel or a screw threaded arrangement whereby adjacent surfaces of a swivel joint can be clamped together when a desired position has been achieved.
Typically, the ball joint type arrangement becomes ineffective due to wear on the ball surface while with the clamping arrangement the continual clamping and releasing of the abutting surfaces can frequently result in stress fractures of the material occurring.
The present invention in another embodiment thereof also relates to an improved document holder.
To the present time various difficulties have been experienced with document holders which are required by secretaries, data processors and the like to hold a document while it is being worked on at the typewriter or computer terminal for exammple. Other instances where document holders are used are of course where a document is to be held merely for it to be read e.g. as a book or magazine holder.
A major difficulty with document holders available at the present time has been the effective retention in a desired place of the cursor i.e. the transverse bar which traverses the document from top to bottom. Another disadvantage of existing document holders has been the inability of the cursor to accommodate various thicknesses of document.